DE202007010030U1 - Seat with a seat part and an integrally formed back comprehensive bowl made of plastic - Google Patents

Abstract

Seat comprising a seat part and a backrest formed thereon Tray made of plastic, characterized in that the shell (4) a composite body from a shell casing (5) and one with the shell casing (5) shear-resistant bonded, fiber-reinforced plastic core (6) forms.

Description

The The invention relates to a seat with a seat part and a molded thereon back comprehensive bowl made of plastic, as well a method for producing such a seat.

such Seat shells have become common made of solid material with a plastic component. To can be used as a shell material, for example polyamide, be made with the rather thick-walled and very stiff seats can, the almost no elasticity exhibit. Shall created seats with improved elasticity So far, the material used for the seats is polypropylene used. This results in very soft seat shells, the Stiffening on the back be equipped with close-meshed and high stiffening ribs have to. such Seats are suitable because of their poor cleaning ability but hardly for a rough everyday operation, such as in school or have a considerable size and thus also space, especially when stacking, on.

Of Further can Such seats or seat shells are formed by a blow molding, including a plastic blank, for example a cylinder or the like, in an open one Mold inserted and then the seat shape by blowing air or the like. In the heated plastic blank is formed and cured in a closed mold. It comes as Shell material usually polypropylene used and results in the shell naturally a cavity, whereby such trays in turn have a relatively large footprint and due the construction is relatively stiff are, with the freedom in the surface formability is also limited.

outgoing from a prior art of the kind described the invention of the object to provide a seat, the one possible thin flexible seat shell with as possible smooth surface and having sufficient strength.

The Invention solves this task by making the shell a composite body a shell jacket and a shear-resistant connected to the shell, fiber reinforced Plastic core forms.

With The invention provides a simple way the possibility of a elastic, very thin-walled Seat to manufacture, which does not require stiffening ribs and thereby through the fiber reinforced Plastic core has sufficient strength. This can the shell of a relatively soft Made of plastic, with a smooth, easy to clean surface can be achieved is. It also ensures that a fiber-free, but little Wear on Clothing-causing plastic forms the outer skin of the shell. The desired Strength or rigidity of the shell is achieved by the fiber-reinforced plastic core certainly. By an appropriate choice of the plastic core, in particular also the thickness, the flexibility of the shell can thus over long Areas are set. With the invention, a shell Made of plastic, the backrest area elastically deformable is, thus a dynamic seating behavior allows while still a offers sufficient resistance to breakage.

Around To ensure a sufficient strength of the seat with a long service life It is recommended that the plastic core and the shell shell off the same plastic or similar plastics and the plastic core is preferably reinforced with glass fibers. If the plastic core and shell are made of the same plastic, is ensured with appropriate manufacturing that shell jacket and plastic core, for example, by a smooth transition in the plastic shear-resistant connected to each other. Be for the shell coat and the plastic core does not use the same plastics so it is important to ensure that, for example, by melting together glued plastics are used, wherein for this Case preferably approximately equal high melting points for Both plastics are to be demanded.

to solution the task of the invention It has proven to be particularly advantageous if both the plastic core as well as the plastic sheath made of polypropylene exist, especially since the polypropylene itself is very soft is and thus form a very pleasant to use seat shell leaves. However, this softness also has the advantage that the fiber-reinforced polypropylene for the Core high strength with low brittle fracture tendency and thus a corresponding high flexibility the seat, in particular the seat back guaranteed. This can be a especially thin-walled, flexible seat shell are created with appropriate strength can.

Become placed on the seat particularly high strength requirements, the plastic for the shell coat also fiber reinforced be, in turn, glass fibers or more preferably softer Fibers such as textile fibers, carbon fibers, natural fibers od. Like. Use can find.

A seat according to the invention can be manufactured particularly cost-effectively and advantageously by injection molding in an injection mold, wherein a method for producing a seat according to the invention is characterized in particular in that first the plastic for the shell casing is introduced into an injection mold for the shell and then the glass-reinforced plastic for the core is injected into the injection mold before the plastic of the shell completely solidifies. The plastic for the shell casing and the plastic for the plastic core are preferably introduced immediately after one another into the injection mold. The plastic for the shell jacket is first introduced into the shell so that it remains molten in its core area. Subsequently, the glass fiber reinforced plastic core is injected with displacement of the plastic for the shell casing in the mold until the injection mold is completely filled. The fact that the plastic for the shell casing is pushed in front of the core plastic during the injection of the core plastic and thereby cools and adheres to the injection molding shell ensures that the seat has a perfect shell casing of fiber-free plastic after a finished molding of the injection mold, which surrounds the fiber-reinforced plastic core clean.

The Invention is schematically in the drawing using an exemplary embodiment shown. Show it

1 a seat according to the invention in cross section and

2 and 3 an injection mold in cross section to illustrate the production steps for producing a seat according to the invention.

An inventive seat 1 From a plastic shell includes a seat part 2 and a molded backrest 3 , In order to create a thin-walled flexible seat shell with the smoothest possible surface and sufficient strength, forms the shell 4 a composite body of a shell casing 5 and one with the shell 5 shear-resistant bonded, fiber-reinforced plastic core 6 , In the illustrated embodiment, the shell casing consist 5 and the fiber reinforced plastic core 6 made of polypropylene and is the plastic core 6 reinforced with glass fibers.

2 and 3 show schematically an injection mold 7 with two of the seat pan mold between them forming injection mold halves 8th . 9 Belonging to an injection molding machine, not shown in detail and in the usual manner to each other braced or for demolding the finished seat from each other are solvable. For the manufacture of a seat according to the invention is first the plastic 10 for the shell coat 5 in the injection mold 7 for the shell 4 introduced (see 2 ), after which the glass fiber reinforced plastic 11 for the fiber-reinforced plastic core 6 in the injection mold 7 is injected before the plastic of the shell jacket 5 completely frozen ( 3 ). When injecting the plastic 11 for the core in the injection mold 7 becomes the plastic 10 for the shell coat 5 in front of the plastic 11 pushed for the core, attaches to the shell surface, where it adheres and at least begins to harden, thereby ensuring that the shell shell 5 forms a clean continuous surface, which encloses the core over its entire surface. By controlling the injection speed, injection mold temperature u. Like. Can the thickness of core and shell set.

Claims (4)

Seat comprising a plastic shell comprising a seat part and a back formed thereon, characterized in that the shell ( 4 ) a composite body of a shell casing ( 5 ) and one with the shell jacket ( 5 ) shear-resistant bonded, fiber-reinforced plastic core ( 6 ). Seat according to claim 1, characterized in that the plastic core ( 6 ) and shell jacket ( 5 ) consist of the same plastic or similar plastics and the plastic core ( 6 ) is preferably fiber-reinforced with glass fibers. Seat according to claim 1 or 2, characterized that both the plastic core as well as the plastic sheath made of polypropylene consist. Seat according to one of claims 1 to 3, characterized in that the plastic ( 10 ) for the shell casing ( 5 ) is fiber reinforced.